Enthalpy of fusion

The analysis of the enthalpy of fusion consists of measuring the quantity of thermal energy required to change a material from a solid state to a liquid state . This thermodynamic quantity, expressed in joules per gram (J/g) or kilojoules per mole (kJ/mol), is decisive for evaluating the purity , thermal stability and crystalline structure of a product.

The measurement of the enthalpy of fusion is carried out using differential scanning calorimetry (DSC) , a reference method in materials science. By recording the heat absorbed during fusion, DSC makes it possible to quantify phase transitions and identify impurities or polymorphisms.

Experimental methods and protocols

The test is carried out using a differential calorimeter which compares the heat flow between a sample and an inert reference subjected to the same temperature rise.
During melting, a net absorption of heat is recorded, the peak area of ​​which corresponds to the enthalpy of fusion.

Controlled parameters include:

• The heating speed ,
• The mass of the sample ,
• The gaseous atmosphere (nitrogen, air, helium),
• And the temperature range suitable for the matrix.

ISO 11357 (for polymers) and ASTM E794 standards .

Industrial and scientific applications

The enthalpy of fusion is an essential indicator in many fields:

• Cosmetics and pharmaceuticals : study of the thermal stability of waxes, butters, excipients, active ingredients.
• Food industry and nutraceuticals : characterization of the crystallization of fats, cocoa butters, or plant extracts.
• Materials and polymers : evaluation of the degree of crystallinity, purity and structural modifications after aging or heat treatment.
• Environment and chemistry : analysis of organic or mineral compounds to determine their thermal behavior.

The results make it possible to determine:

• The melting temperature (Tf) ,
• The enthalpy of fusion (ΔHf) ,
• The degree of crystallinity (in the case of polymers),
• And the comparison of batches or formulations for quality control.

Related analyses

For a complete thermal characterization, YesWeLab recommends combining this study with:

• Thermogravimetry (TGA / ATG) to observe mass losses,
• Enthalpy of vaporization to study the liquid-gas transition,
• Heat capacity to determine the specific heat of the material.

Interpretation and interest of the results

The value of the enthalpy of fusion provides information on:

• Crystal quality ( a low value often indicates impurities),
• The purity of a compound (correlation between Tf and ΔHf),
• The effects of thermal aging on stability,
• And the comparison between formulations (finished products, production batches, competitor samples).

This analysis is particularly useful for:

• control of raw materials ,
• Validation of thermal processes ,
• Optimization of the texture or fusion of cosmetic or food products.

YesWeLab expertise

YesWeLab provides you with its network of ISO 17025 and COFRAC accredited partner laboratories , experts in advanced thermal analyses .

Thanks to the YesWeLab platform , you can:

• Order your thermal analyses online,
• Track your samples and results in real time,
• Centralize your technical and regulatory reports.